What is meant by Tenderness to Palpation (TTP) of the medial aspect of the knee joint?

What is Tenderness to Palpation (TTP) of the Medial Aspect of the Knee Joint?

TTP of the medial aspect of the knee joint refers to pain elicited when the examiner applies pressure to the medial (inner) side of the knee, specifically over structures including the medial tibial plateau, medial joint line, medial collateral ligament, and surrounding soft tissues.

Clinical Significance and Diagnostic Value

Palpation-induced tenderness represents well-localized pain that typically matches the quality and location of pain experienced during activity 1. This finding is a fundamental component of the physical examination when evaluating knee pathology.

Key Anatomical Locations to Palpate

When examining for medial knee TTP, systematically palpate:

• Medial joint line: Most commonly tender with meniscal tears, though joint line tenderness alone has only 50% sensitivity and 61.7% specificity for medial meniscus tears 2
• Medial tibial plateau: Tenderness here, especially with acute onset pain, may indicate tibial plateau osteonecrosis or stress fractures 3, 4
• Medial collateral ligament: Tenderness along the ligament course suggests MCL injury 5
• Adductor tubercle, gastrocnemius tubercle, and medial epicondyle: These bony prominences are important landmarks for accurate localization 5

Common Pathologies Associated with Medial TTP

Medial Meniscus Tears

• Joint line tenderness is present but has limited diagnostic accuracy when used alone 2
• The presence of medial joint line tenderness should prompt consideration of MRI if symptoms persist after conservative treatment, but should not be used as the sole indication for arthroscopy 6

Tibial Plateau Osteonecrosis

• Acute pain with marked tenderness over the medial tibial plateau in elderly patients is characteristic of tibial plateau osteonecrosis 3, 4
• Initial radiographs may be normal, but bone scans show focal increased uptake and MRI reveals discrete areas of low signal intensity 3
• This condition can be confused with meniscal tears, leading to unnecessary arthroscopy if not recognized 3, 4

Medial Compartment Osteoarthritis

• Pain on palpation of the medial knee is strongly associated with the presence of medial osteophytes 7
• The medial compartment bears 70-80% of joint load during gait, making it the most frequently affected compartment in knee OA 1
• Medial osteophytes are independent predictors of WOMAC pain scores 7

Medial Collateral Ligament Injuries

• Tenderness along the MCL course combined with valgus stress testing helps diagnose MCL injuries 5
• These are the most common knee ligament injuries, typically occurring from valgus contact or external rotation forces 5

Critical Diagnostic Pitfalls

Do not rely on medial joint line tenderness alone to diagnose meniscal pathology - it has poor diagnostic accuracy (56.45%) when used as an isolated finding 2. Clinical tests should be combined with patient history and, when indicated, imaging studies.

Do not attribute all medial knee tenderness to meniscal tears in elderly patients - tibial plateau osteonecrosis presents with similar findings but requires different management 3, 4. Failure to recognize this can lead to unnecessary arthroscopy.

Do not assume tenderness indicates surgical pathology - many conditions causing medial TTP respond to conservative management, including physical therapy and activity modification 6.

Integration with Other Examination Findings

TTP should be interpreted alongside:

• Range of motion testing: Often limited on the symptomatic side with tendinopathy or significant pathology 1
• Inspection for swelling, erythema, and effusion: Joint effusions are uncommon with isolated tendinopathy and suggest intra-articular pathology 1
• Functional testing: Physical maneuvers that simulate tendon loading help confirm tendinopathy 1
• Valgus stress testing: Essential for evaluating MCL integrity 5